This application claims the benefit of a Japanese Patent Application No. 2002-274724 filed Sep. 20, 2002, in the Japanese Patent Office, the disclosure of which is hereby incorporated by reference.
1. Field of the Invention
The present invention generally relates to, and more particularly to imaging optical systems, image display apparatuses and imaging optical apparatuses, and more particularly to an imaging optical system for imaging a bundle of rays from a light modulator element, an image display apparatus which uses such an imaging optical system, and an imaging optical apparatus which uses such an imaging optical system.
The present invention is applicable to scanning optical systems, projecting apparatuses such as liquid crystal projectors and Digital Micro-Mirror Device (DMD, registered trademark) projectors, on-vehicle navigators, various display apparatuses, imaging optical systems for Light Emitting Diodes Array (LEDA) printers, and the like.
2. Description of the Related Art
Conventionally, a liquid crystal projector or the like is used as an image display apparatus. The liquid crystal projector displays a two-dimensional image which is displayed on a liquid crystal panel or the like, by projecting and imaging the two-dimensional image on a screen via a projection lens. When displaying a color image by the liquid crystal projector, images of red (R), green (G) and blue (B) components are displayed on three corresponding liquid crystal panels, and the three liquid crystal panels are illuminated by illumination lights of the corresponding colors, so as to obtain image lights which are spatially modulated depending on the images. The image lights of the corresponding colors are combined, and then projected and imaged on the screen via the projection lens, so as to display the color image.
In the image display apparatus described above, the image which is to be displayed is displayed two-dimensionally on the liquid crystal panel or the like. For this reason, a two-dimensional element, such as the liquid crystal panel, is required as a light modulator element for displaying the image. However, it is difficult to reduce the size of such a light modulator element, and consequently, it is difficult to reduce the size of the image display apparatus which employs such a light modulator element.
Recently, another light modulator element has been proposed, which may replace the liquid crystal panel or the like. This light modulator element is made up of extremely small light modulator parts which are arranged one-dimensionally. Hence, an image display apparatus has been proposed, which images a one-dimensional image on a display surface by use of this light modulator element, and deflects and scans the one-dimensional image at a high speed in a direction perpendicular to a longitudinal direction of the one-dimensional image, so as to display a projected image. This image display apparatus is proposed in R. W. Corrigan et al., “Calibration of a Scanned Linear Grating Light Valve™ Projection System”, Presented at Society for Information Display Symposium, May 18, 1999 San Jose, Calif. (http://www.siliconlight.com/htmlpgs/glvtechframes/glvmainframeset.html).
On the other hand, a Japanese Laid-Open Patent Application No. 2002-214550 proposes achieving modulation by deforming a reflection layer to change a direction of reflected light by use of the light modulator element which is made up of extremely small light modulator parts which are arranged one-dimensionally.
The light modulator element which is made up of extremely small light modulator parts which are arranged one-dimensionally has only been developed recently, and there are demands to realize an imaging optical system suited for imaging light from this light modulator element on a display surface. There are also demands to realize an image display apparatus and an imaging optical apparatus which use the imaging optical system and the light modulator element, and are compact and capable of displaying a satisfactory image and particularly capable of displaying a satisfactory color image.